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by
Y. Ozeki |
Total Records (
5 ) for
Y. Ozeki |
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S.M.A. Kawsar
,
E. Huq
,
N. Nahar
and
Y. Ozeki
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Extracts of Macrotyloma uniflorum plants were
examined as potential sources of phenolic compounds. Reversed phase high
performance liquid chromatography (RP-HPLC) with UV detection was employed
for the identification and quantification of the phenolic acids. Eight
phenolic acids, namely, 3, 4-dihydroxy benzoic, p-hydroxy benzoic,
vanillic, caffeic, p-coumeric, ferulic, syringic and sinapic acids
were isolated from an ethanolic extract of Macrotyloma uniflorum.
The most abundant phenolic acids were p-coumaric acid (8.95 mg
10-2 g of dry sample) and p-hydroxy benzoic acid (7.81
mg/100 g of dry sample). |
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S.M.A. Kawsar
,
G. Mostafa
,
E. Huq
,
N. Nahar
and
Y. Ozeki
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The bioactivity guided separation of the dichloromethane
extract of the aerial parts of Macrotyloma uniflorum Linn. resulted
in the isolation of methyl ester of hexadecanoic and ethyl ester of hexadecanoic
acid mixture (I) and n-hexadecanoic acid (II). The structures of the isolated
compounds were elucidated by spectroscopic analysis, including UV, IR,
1H-NMR, 13C-NMR and mass spectroscopy. In addition,
the fractionated crude extract of 1-butanol exhibited the significant
hemolytic activity by using mouse erythrocytes. |
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Y. Fujii
,
S.M.A. Kawsar
,
R. Matsumoto
,
H. Yasumitsu
,
N. Kojima
and
Y. Ozeki
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To find novel carbohydrate-binding proteins (lectins) from marine invertebrates to understand the binding mechanism of the protein and to apply it for glycan-dependent diagnostics and/or glycoconjugates capture technology. A D-galactoside-binding lectin was purified from foot of bladder moon shell, Glossaulax didyma by lactosyl-agarose affinity chromatography. The crude supernatant by Tris-buffered saline had strong hemagglutination activity against trypsinized and glutaraldehyde-fixed human erythrocyte. However, the activity was not inhibited by any tested saccharides and chilete reagents. On the other hand, the dialyzed crude supernatant obtained from the precipitates with 100 mM lactose in Tris-buffered saline had also hemagglutination activity inhibited by β-galactoside and D-galactose. The lectin was purified with lactosyl-agarose affinity chromatography. The molecular mass of the lectin was determined to be 60 kDa by SDS-PAGE under reducing and non-reducing conditions and being a 60 kDa polypeptide monomer by gel permeation chromatography. The association-rate constant (kass) and dissociation-rate constant (kdiss) determined for the lectin against asialofetuin was determined as 5.4x104 M-1sec-1 and 7.2x10-3sec-1, respectively. Lectin-conjugated Sepharose gel captured asialofetuin and eluted it by lactose-containing buffer from the gel, indicating that the lectin could catch the asialoglycoprotein. It was concluded that a many amount of a D-galactoside-binding lectin which can catch asialoglycoprotein presents in foot of the bladder moon shell. |
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N Sasaki
,
Y Abe
,
Y Goda
,
T Adachi
,
K Kasahara
and
Y. Ozeki
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Betalains are synthesized in flowers, fruits and other tissues of the plant order Caryophyllales. Betalamic acid is the chromophore of betalain pigments synthesized by a ring-cleaving enzyme reaction on l-dihydroxyphenylalanine (DOPA). Although reverse genetic evidence has proven that DOPA 4,5-dioxygenase (DOD) is a key enzyme of betalain biosynthesis, all attempts to detect recombinant plant DOD activity in vitro have failed. Here, we report on the formation of betalamic acid from DOPA under suitable assay conditions using recombinant MjDOD produced by Escherichia coli. This is the first report showing biochemical evidence for DOD activity in vitro. |
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